It's 1. Melting a substance. The rest are chemical changes
To form a salt compound, the acid contribute a NON METAL ION and the base contributes a METAL ION.
In chemistry, acid and base react together to form salt and water only. For the salt formed, the positive metal ion comes from the base while the negative non metal ion comes from the acid.
Answer:
40.8g of sodium sulfate must be added
Explanation:
The reaction of barium nitrate, Ba(NO₃)₂ with sodium sulfate, Na₂SO₄ is:
Ba(NO₃)₂ + Na₂SO₄ → 2 NaNO₃ + BaSO₄(s)
That means, for a complete reaction of an amount of barium nitrate you must add the same amount in moles of sodium sulfate. To solve this problem we need to convert the mass of barium nitrate to moles = Moles of sodium sulfate that must be added:
<em>Moles Ba(NO₃)₂ -Molar mass: 261.3g/mol-:</em>
75g * (1mol / 261.3g) = 0.287 moles = Moles Na₂SO₄
<em>Mass Na₂SO₄ -Molar mass: 142.04g/mol-:</em>
0.287 moles * (142.04g / mol) =
<h3>40.8g of sodium sulfate must be added</h3>